The invention concerns a pipe connection, in particular a gas tight pipe screw connection wherein the parts in the connecting region are connected by means of joining according to DIN 8593 by way of contact-pressing and insert-pressing, comprising an inner pipe part and an outer pipe part, or two inner pipe parts with an outer collar.
Pipes, mostly seamless pipes that can be formed from different materials, are utilized for the conveyance of oil field- and/or gas field products vertically and horizontally also over large distances and require, because of the significant demands, a high sealing quality of the connections during practical operation or application.
A pipe connection that has already been utilized over the long term, and represents essentially prior art in regard to the geometric basic concepts, is designed in such a manner that an inner pipe part and an outer pipe part features sealing surfaces that are truncated cone shaped and abut against one another, with an inclination toward one another in the distal direction of the inner pipe part of about 1:10, and that act together with stop surfaces that are truncated cone shaped and are aligned opposite the axis direction. A sealing effect can thereby be achieved by means of a mutual, axial contact-pressing (fully engaged) of the pipe endings for example by means of a thread connection or similar.
In order to improve the tightness or the quality of the pipe connection in the case of the demands on the pipe lines present in the field, but also to achieve in the case of a dismantling and reassembling of the pipe components maintenance of the sealing quality of the pipe connections, a plurality of geometric embodiment forms have already been proposed with particular design of the seal- and stop surfaces of the connection. Complex sealing surface shapings are however usually associated with higher expenditures for the chip-removing processing of the connecting regions of the pipe endings and with lowered cost effectiveness of manufacture.
The U.S. Pat. No. 7,334,821 B2 discloses a pipe connection with a barrel-shaped sealing surface of the pipe inner part that is convex in cut, followed by a protruding extension with a distal stop surface. Thereby, during full engagement of the pipe connection, the press surfaces of the pipe components are to obtain a higher conicity and achieve an improved sealing effect. The manufacturing effort for the construction of the complex shaped sealing regions appears however to be high.